Professor of History, Macquarie University, Sydney; Author, Maps of Time: An Introduction to Big History

The Idea of "Emergence" or "Emergent Properties"

One of the most beautiful and profound ideas I know, and one whose power is not widely enough appreciated, is the idea of "emergence" or "emergent properties".

When created our Universe was pretty simple. For several hundred million years there were no stars, hardly any atoms more complex than Helium, and of course no planets, no living organisms, no people, no poetry. (The Keck observatory in Hawaii has just found direct evidence of those simple primordial clouds of matter!)

Then, over 13.7 billion years, all these things have appeared, one by one. Each had qualities that had never been seen before. This is 'creativity' in its most basic and mysterious form. Galaxies and Stars were the first large, complex objects. And they had strange new properties. Stars fused Hydrogen atoms into Helium atoms, creating vast amounts of energy and forming hot spots dotted through the Universe. In their death throes, the largest stars created all the elements of the Periodic Table, while the energy they pumped into the cold space around them helped assemble these elements into utterly new forms of matter with entirely new properties. Now it was possible to form planets, bacteria dinosaurs and us!

Where did all these exotic new things come from? How do new things, new qualities 'emerge'? Were they present in the components from which they were made? The simplest reductive arguments presume that they had to be. But if so, they can be devilishly hard to find. Can you find 'wateriness' in the atoms of hydrogen and oxygen that form water molecules? This is why 'emergence' so often seems magical and mysterious.

But it's not, really. One of the most beautiful explanations of emergence that I know can be found in a Buddhist sutra that was probably composed more than 2,000 years ago: "The Questions of Milinda". (I'm paraphrasing on the basis of an online translation).

Milinda is a great emperor. He was actually a historical figure, the Greco-Bactrian emperor, Menander, who ruled a Central Asian kingdom founded by generals from Alexander the Great's army. In the sutra, Milinda meets with Nagasena, a great Buddhist sage. They probably met in the plains of modern Afghanistan, over 2,000 years ago. Milinda had summoned Nagasena because he was getting interested in Buddhism, but was puzzled because the Buddha seemed to deny the reality of the 'self'. Yet for most of us, the sense of self is the very bedrock of reality. (When Descartes said "I think, therefore I am", I think he meant something like: "The self is the only thing we know that exists for certain.")

So we should imagine Milinda sitting in a royal chariot, followed by a huge retinue of courtiers and soldiers, meeting Nagasena, with his retinue of Buddhist monks for a great debate about the nature of the self, reality and creativity. It's a splendid vision.

Milinda asks Nagasena to explain the Buddha's idea of the 'self'. Nagasena asks: "Sire, how did you come here?" Milinda says: "In a chariot, of course, reverend Sire!" "Sire, if you removed the wheels would it still be a chariot?" "Yes, of course it would," says Milinda with some irritation, wondering where this conversation is going. "And if you removed the framework, or the flag-staff, or the yoke, or the reins, or the goadstick, would it still be a chariot?" Eventually Milinda starts to get it. He admits that at some point his chariot would no longer be a chariot because it would have lost the quality of 'chariotness' and could no longer do what chariots do.

And now, Nagasena cannot resist gloating because Milinda has failed to define in what exact sense his chariot really exists. Then comes the punch line: "Your Majesty has spoken well about the chariot. It is just so with me. … This denomination 'Nagasena,' is a mere name. In ultimate reality this person cannot be apprehended."

Or, in modern language, I, and all the complex things around me, exist only because many things were assembled in a very precise way. The 'emergent' properties are not magical. They are really there and eventually they may start re-arranging the environments that generated them. But they don't exist 'in' the bits and pieces that made them; they emerge from the arrangement of those bits and pieces in very precise ways. And that is also true of the emergent entities known as "you" and "me".